What Is WebP? The Modern Image Format Explained

This article provides an overview of WebP, a modern image format designed specifically for the web. You will learn what WebP is, how it compresses image data without sacrificing quality, how it compares to legacy formats like JPEG and PNG, and where to find dedicated resources to implement it on your website.

Understanding WebP

WebP is an open-source raster image file format developed by Google in 2010. Its primary purpose is to create smaller, richer images that make the web faster. By significantly reducing file sizes compared to traditional formats, WebP helps websites load faster, consume less bandwidth, and deliver a better user experience.

To explore documentation, specifications, and conversion tools, you can refer to the WebP (Web Picture) resource website.

How WebP Compression Works

WebP achieves superior compression using two distinct methods:

• Lossy Compression: Based on the VP8 video codec, lossy WebP uses predictive coding to predict the values of neighboring pixels. It only encodes the difference between the predicted values and the actual values, discarding redundant data. On average, lossy WebP images are 25% to 34% smaller than comparable JPEG images.
• Lossless Compression: WebP lossless compression uses advanced techniques such as spatial transformation, color transform, and entropy coding to reconstruct original pixels exactly. Lossless WebP images are typically 26% smaller than equivalent PNG images.

Key Features and Advantages

• Alpha Channel Support: Unlike JPEG, lossy WebP supports transparency with only a minor increase in file size.
• Animation: WebP can replace animated GIFs, supporting both lossy and lossless frames with 24-bit color and 8-bit transparency, producing substantially smaller files.
• Reduced Bandwidth and Storage: Smaller asset sizes reduce hosting bandwidth costs and server storage requirements.
• Better Core Web Vitals: Faster load times directly improve Largest Contentful Paint (LCP) scores, aiding search engine rankings.

Browser Support

WebP is natively supported by all major modern web browsers, including Google Chrome, Mozilla Firefox, Apple Safari, Microsoft Edge, and Opera. For older legacy browsers, websites can serve fallback JPEG or PNG images using the standard HTML <picture> element.